PROJECT SUMMARY Nearly 90% of drugs under development fail to reach the market. Many of these failures occur due to cardiotoxicity, usually when the candidate molecule induces cardiac arrhythmias. In a few notable cases, some drugs pass pre-clinical screens and clinical trials, only to be removed from the market once toxic effects are discovered in large patient populations. These failures represent a tremendous source of waste and constitute a significant part of the ~$2 billion cost of bringing a single drug to market. Consequently, the FDA now mandates that all drugs undergo in vitro cardiotoxicity testing before being tested in humans. This has led to a significant and growing market for tools and technologies that enable earlier detection of toxic effects before exposure to patients. However, current screening methods fall short of predicting how a drug will behave in the body; indeed there is a pressing need for more predictive model systems. Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) are an attractive model for in vitro preclinical toxicity screening; they are relatively easy to maintain, are derived from human tissue, and have the potential to reduce the need for animal experimentation. However, at present, iPSC-CM based assays do not properly replicate the function of the human heart. These cells exhibit phenotypes similar to that of fetal tissue and do not respond as expected to drugs of known effect; in some cases, known bad-actor drugs fail to induce arrhythmias, while others only show in vivo cardiotoxicity when exposed to supra-physiological doses of the drug in question. The drug discovery industry and its regulators realize the potential of iPSC-CMs for early cardiotoxicity screening, but also understand that?at present?there are significant limitations to their use in the drug development process. Thus, it is clear that the production of mature cardiac tissues that accurately recapitulate in vivo drug responses represents a significant opportunity for reducing cost and waste in drug development. NanoSurface Biomedical, Inc., aims to develop an enhanced iPSC-CM cell line that has been optimized for highly predictive drug-induced cardiotoxicity screening. We hypothesize that iPSC-CMs that give more predictive results in in vitro cardiotoxicity detection can be made by combining nanoscale extracellular cues with biochemical and molecular biological stimuli that drive their maturation. We will first focus on demonstrating that these enhanced iPSC-CMs can correctly classify drugs that are currently improperly screened (Phase 1, Aim 1). After validation, we will generate a stable cell line that encompasses the maturation factors determined in Phase 1 in preparation for scaling and commercial production (Phase 2, Aim 1). Commercialization efforts will further be facilitated by characterizing transcriptomic, structural, and functional phenotypes of the predictive cell line and in identifying a set of key physiological metrics that will be used for in-line quality control (Phase 2, Aim 2). Last, we will validate and generate data for market release with our research partners in the drug development industry and regulatory bodies (Phase 2, Aim 3).